Even league officials, players and their families will be subject to such measures.

The league said Tuesday that spectators who don’t consent to the security requirements will be refused admission. The draft begins Thursday night (first round) and has sessions Friday night (second and third rounds) and Saturday afternoon (rounds four, five, six and seven).

“In light of the current state of affairs, we decided to make adjustments for the fans’ safety,” NFL security chief Jeff Miller told The Associated Press. “We had a concern about individuals that might want to replicate what occurred or approach another sporting type event. This is the first large event in New York City on the sports events side since the events in Boston.”

Those adjustments also will mean about 20 percent more security personnel and increased K-9 explosive detective teams on site.

New York police and draft organizers are recommending spectators minimize the number and size of all items carried into Radio City. Fans are urged to bring nothing larger than a small purse. Large backpacks have been banned for some time.

Prohibited items also include beverages, footballs and beach balls, noisemakers and horns.

Lines to enter the theater are expected to be lengthy and the NFL is urging fans to arrive early.

“There will be some very visible things and we’ll also be doing things behind the scenes that people won’t notice,” Miller said, noting the league is working closely with the NYPD, federal authorities and private security firms.

Miller was contacting some two dozen draft prospects who were invited to attend, along with their family members, to alert them to the enhanced security arrangements. He made it clear that when the league says everyone will be subject to the security checks, it means everyone.

“It includes me and my staff, and the commissioner, the players and families,” Miller said. “This is an immediate response to what we saw last week.”